This is pretty much a finished addendum to the non toxic tek. It has worked several times for SWIM, and he feels that it would work for anyone who carefully follows the steps outlined.
SWIM will make a pictorial of this method next time he tries it, just to give you guys an idea of the stuff he ends up with (pure white mescaline, using all food-safe materials).
The trick may be in the extreme shaking under pressure. This is why SWIM suggests a limonene tested soda bottle, to hold the pressure. It also may be necessary - in order to attain pure mescaline - to ONLY do seltzer pulls, and no vinegar pulls. This will make it more likely to come out clean, dry, and white - and if not, it can be cleaned with IPA (which 69ron mentions mescaline acetate to be soluble in). If one wants an alkaloid mix, of course, it is wise to do many kinds of saltings.
Now the wait for SWIM to get around to getting some more cactus....